The goal of this application is to develop a transmission blocking vaccine to Plasmodium falciparum. This vaccine is meant to induce antibodies which bind to antigens present on the surface of male and female gameites and parasites developing in the mosquito midgut. The main candidate antigen is Pfs25, a surface protein that is expressed at the onset of gametogenesis. The vaccine will be based on DNA vaccines given either alone or in a prime-boast regimen with protein vaccines.